There has been an increase in the number of the additive functions of the copying machine, resulting in a complicated operation to such an extent that the user cannot make use of all functions. Since he does not know how copying is performed, he has to make several test copies to get a copy having the desired dimensions, layout and colors. Since he is not very fond of such test copies, he has often avoided using effective additive functions. To assist understanding of the user for solution of this problem, a little larger display unit has been provided, and the messages have been displayed in kanji (Chinese characters) or hiragana (Japanese characters), or editors or a variety of semiautomatic functions have been added, which have been insufficient in the following respects: For example, it is not easy for the user to determine what magnification should be selected to get the desired size in the case of the zooming function. Some machines provide the automatic magnification setting function; however, since it uses the method of calculating magnification according to the specified paper size, it cannot meet the requirement of magnifying part of the original, for example.
Some machines calculate the magnification rate from input values on the coordinates, but this requires precise user operation, often resulting in operation errors. With respect to density adjustment and color balance, several test copies must often be taken to determine the influence given to the picture by one graduation on the adjust button. Namely, the display on the conventional control section has failed to determine if the current setting is correct to get the desired copy style, therefore, a considerable experience has been required to make an effective use of the additive function without test copies. Furthermore, the unit price for the full-color copy has been much higher than that of the black/white copy, so it is uneconomical to take many test copies.
The primary objective of the present invention is to provide the digital copying machine featuring extremely excellent maneuverability, which permits pictorial confirmation of the copy style, to ensure precise operation of the additive function by eliminating the need of test copies when the additive function is used, as described above.
The present invention relates to the color balance control device which, as the said additive function operating device eliminating the need of test copies, converts the colored original including photographs and printed matters into electric signals, these signals being output on the color television monitor or full color printer via the control circuit.
Color balance in the conventional full color copy mode has been controlled by adjusting the magnitude of the signals for red, green and blue, or cyan, magenta and yellow (black) constituting the color components by the control key on the control panel. In this case, some knowledge or skill on color mixing has been required for the operation, and this has been difficult for normal users. For example, when the entire page of the original is brownish, color balance can be controlled so as to cancel it. The user has to operate the control key to control the color balance while considering color components of the brown, their ratio and quality. This control is not very easy for the user who has little knowledge about color mixing, often causing operation errors.
This present invention provides an easy-to-use means for color balance control by electronic means to solve the said problems.
For the user with little knowledge about color mixing, it is easy to specify the color to be output as achromatic color (gray) in the original. For example, it can be easily considered that the black character or the paper texture should be adjusted to in achromatic color in general cases. When the original is output on the color display screen or the paper, the user can easily identify if the part to be output in achromatic color (black character or the paper texture) is covered with several colors. He can easily identify the case when the entire paper is covered by colors.
Thus, the second object in the present invention is to provide the color balance control device which ensures that all colors are adjusted as the user desires and that the expected gray part is certainly output in gray, if the user identifies the said colors and specified them, without having to consider the color components.